Press-on, twist-off tamper indicating closure cap

ABSTRACT

A tamper-indicating closure is provided of a type wherein a closure cap having a side liner is pushed on-to a threaded finish so as to form complementary threads in the liner for twistably removing the cap. A resiliently expansible plastic ring is held in the cap skirt against rotation and endwise movement relative thereto. An inturned lip on the ring engages under a collar on the finish below the threads when the cap is pushed on. The edge of the lip also engages serrations around the finish. When the cap is twisted for removal, the engagement of the lip under the collar and with the serrations inhibits rise and rotation of the cap. The applied torque causes rupture of a series of frangible bridges forming a band around the skirt, whereafter the upper portion of the cap twists off.

United States Patent Westfall [541 PRESS-ON, TWIST-OFF TAMPER INDICATINGCLOSURE CAP [72] Inventor: James E. Westfall, Western Springs,

[73] Assignee: Continental Can Company, New

York, NY.

22 Filed: Dec.2,1970

[21'] Appl.No.: 94,367

[52] U.S. Cl. ..2l5/42 [51] Int. Cl. ..B65d 41/02 [58] Field of Search..2l5/9, 42, 38

[56] References Cited UNITED STATES PATENTS 3,460,703 8/1969 Leftault,Jr. ..215/42 X 3,441,161 4/1969 Van Baarn ..215/42X FOREIGN PATENTS ORAPPLICATIONS 1,188,075 4/1970 Great Britain ..2l5/42 [1 1 3,685,677 [451Aug. 22, 1972 Primary ExaminerM. Henson Wood, J r.

Assistant Examiner-Michael Y. Mar Attorney-Americus Mitchell, Joseph E.Kerwin and William A. Dittmann ABSTRACT A tamper-indicating closure isprovided of a type wherein a closure cap having a side liner is pushedonto a threaded finish so as to form complementary threads in the linerfor twistably removing the cap. A resiliently expansible plastic ring isheld in the cap skirt against rotation and endwise movement relativethereto. An intumed lip on the ring engages under a collar on the finishbelow the threads when the cap is pushed on. The edge of the lip alsoengages serrations around the finish. When the cap is twisted forremoval, the engagement of the lip under the collar and with theserrations inhibits rise and rotation of the cap. The applied torquecauses rupture of a series of frangible bridges forming a band aroundthe skirt,

whereafter the upper portion of the cap twists off.

7 Clains, 6 Drawing Figures PATENTEDmczz I972 SHEET 1 0F 2 llll INVENTORJAMES E. WESTFALL ATT'Y.

PATENTEDwszz m2 SHEET 2 OF 2 l l l I III llll l INVENTOR JAMES E.WESTFALL PRESS-N, TWIST-OFF TAMPER INDICATING CLOSURE CAP Thisinvention, relates to closures of a tamper-indicating type, moreparticularly a closure cap of the push-on, twist-off type for a bottlewith a finish having thread formations thereon.

Tamper-resistant caps are popular for-beverage bottles, such as used foralcoholic and various carbonated beverages. There is also a demand fortamper-indicating caps on other bottles or containers which are afrequent target of contents pilferage, such as antifreeze jugs or cans.

Supermarket-style, unsupervised shelving of goods greatly increases theincidence of pilferage. Removal of liquids from easily openable andreclosable containers is often difficult to detect. If the container isopaque, neither the ultimate customer nor the sales clerk may be awarethat some or all the contents has been removed, there being no evidenceof tampering.

A number of designs fortamper-proof" or tamperindicating closure capshave been heretofore proposed. Some have met with substantial success.One such is an aluminum cap which can be pushed over a threaded finishto seal against the container lip, the threads being then rolled in thecap skirt in conformity with the finish threads to form a twistablyremovable closure. The cap is provided with a weakening bank around theskirt below the threads. The marginal portion of the skirt below theweakening band is turned in under a shoulder on the finish, engages withlugs therein, or is otherwise engaged with the neck or shoulder of thebottle to inhibit twist-off. When torque is applied to unscrew the cap,the skirt ruptures at the weakening ban, providing a readily visibletelltale of opening or attempt thereat. Such fracture-band telltale isparticularly desirable for pressurized or vacuumized containers, as inthe case of carbonated beverage bottles, baby food jars, and the like,since tampering is evident even when the cap has been twisted only suchslight amount as may disturb the seal and cause spoilage.

While the roll-on-thread tamper-indicating cap above described isgenerally satisfactory, it is substantially more costly to apply than acrown cap or plain screw cap. Thread rolling in situ involves relativelycomplicated tooling and is rather slow. Furthermore, materials havingthe desirable thread-rolling properties are also generally susceptibleto creep and warpage, whereby the seal and reclosure qualities may beadversely affected.

Heretofore no fully satisfactory means has been found for providing acap of the push-on, twist-off type with a tamper-indicating feature. Theextra cost of orienting the cap to engage lugs, rolling a lip under abead, or like application operations largely offset the savings effectedby push-on application to form the threads in the skirt.

It is a principal object of this invention to provide atamper-indicating closure for bottles or the like of the push-on,twist-off type which is highly effective, yet inexpensive, easy openingand having a good reclosure characteristic.

More particularly, it is an object of this invention to provide atamper-indicating closure cap which can be applied to and fully securedto a container simply by pushing the cap on without special orientationor supplemental operations.

According to this invention, the bottle or jar finish is provided withexternal threads or equivalent retention means. A collar below thethreads defines a downwardly facing shoulder.

The closure cap according to this invention is characterized by agenerally cylindrical skirt, the upper portion of which is adapted forformation of thread therein upon the application of an axial force whichalso effects a seal of the opening and engaging the twist-off inhibitionmeans with cooperating means on the container neck.

The preferred form of the closure cap comprises a shell having a toppanel and a skirt depending therefrom. The generally cylindrical upperportion of the skirt has a plastic liner adapted for wedging over thefinish threads when the skirt is telescoped over the finish, therebyconforming the liner to the finish threads and effecting a side sealsupplementing the top seal effected by liner material inside the coverpanel compressed against the container lip. Such means and method ofeffecting thread engagement and seal are inside diameter of the flangebeing normally smaller than the outside diameter of the aforementionedcollar. The shell skirt and the outer wall of the ring are provided withclosely matched corrugations, obviating relative rotation of the twoparts. The ring is also close ly held between the intumed lip of theskirt and an opposing shoulder, preventing relative endwise movement.After'the ring is inserted into the skirt, then the lip is formed overthe ring to hold the ring in place prior to sealing.

- Below the downwardly facing shoulder of the container, the neck isprovided with a circumferential series of serrations. The ring is sopositioned in the cap that the inwardly extending flange rides over thecollar on the container as the cap is pushed on and then snaps under thedownwardly facing shoulder when the cap in the sealed andthread-engaging position is on the finish. The finish serrations biteinto the inner edge of the intumed flange, inhibiting rotation of thering and the shell.

When torque is applied to twist the cap off the finish, the ring flangeengaged under the collar shoulder inhibits rotation and rise of the cap,so that continued application of torque fractures the bridges. The upperportion of the shell with its liner, comprising a complete screw cap,can then be twisted off and can also be used as a reclosure.

When the bridges are fractured, the severed, lowermost portion of theskirt drops, exposing the plastic ring. The ring may be made of abrightly colored plastic, or bear insignia serving to attract attention,improving its visibility as a telltale of the attempted or actualopening of container even through the upper shell has not been removed,or has been replaced.

Other advantages, objectives and details of the invention are set forthin the ensuing description and accompanying drawings.

FIG. 1 is a partial elevation of a jar, showing the neck and finishportion thereof with a closure according to this invention;

FIG. 2 is a partial cross-sectional view of the closure cap shown inFIG. 1, before application of the cap to the finish;

FIG. 3 is a partial horizontal sectional view taken on line 33 of FIG.2, showing the anti-rotation interlock of the ring insert and the shellskirt;

FIG. 4 is a partial elevational view of the neck of the jar shown inFIG. 1, showing details of the finish thereof; and

FIG. 5 is a partial horizontal sectional view taken on line 5-5 of FIG.4, showing the condition of the closure when sealed;

FIG. 6 is a partial vertical sectional view with the closure added andshowing the anti-rotation serrations under the finish collar providedfor engagement of the insert l'lng.

FIG. 1 shows the top of a jar 10 provided with a closure according tothis invention. Closure cap 11 includes a shell having a top panel 12and a skirt 13. The

upper portion 14 of skirt 13 is generally cylindrical.-

The lower portion 15 is somewhat larger and generally bell-shaped. Skirtportion 15 has a weakening band 16 of the frangible-bridge type, such asthat shown in U. S. Pat. No. 3,484,012 issued to Robert P. White andCharles N. Foster on Dec. 16, 1969.

Referring now to FIG. 2, which shows the internal structure of cap 11before application to the jar, the top panel 12 and upper skirt portion14 are provided with a liner 18 having a top seal portion 19 and aside-seal and thread engagement portion 20 extending substantially thefull length of skirt portion 14. Liner 18 is preferably made ofplastomeric material, formed substantially in accordance with thedescription of such liners in the aforesaid patent, serving the samepurpose in the closure cap of this invention. While the foregoing is thepreferred provision for sealing and skirt thread-formation, it will beunderstood that other forms may be used if desired, such as forsqueeze-on, crimp-on or roll-on thread formation, with any suitablegasket or seal ring, as may be best suited to a particular application,providing same is adapted essentially for push-on application, by andfor securement without relative rotation of the cap and the container.

The bell portion of 14 comprises a generally horizontal flange portion21 defining shoulder 22, cylindrical portion 23 extending therefrom andincluding the weakening band 16. There is another horizontal, outwardlyextending flange 24 from which depends the substantial vertical flangeportion 25. Flange portion 25 terminates in the inturned lip 26.

Bell portion 15 constitutes a cage for retaining the insert ring 27. Assubsequently described, ring 27 serves to inhibit rotation and rise ofthe cap relative to the finish, after the cap has been secured insealing position on the container. Accordingly, ring 27 is held in bellportion 15 in such manner that there can be no relative rotation betweenring 27 and the skirt 13 while the weakening band 16 remains intact. Toobviate relative rotation, ring 27 is splined in skirt portion 15 asbest seen in FIGS. 2 and 3. A number of corrugations 30 are formed inthe lowermost vertical flange portion 25 of the skirt, definingalternating axial ridges and flutes. The number of corrugations areselected according to the size and material of the cap, but thecorrugations are preferably of such number and flute depth as to providea general stiffening effect to the lower portion of the cap skirt andmost particularly a sufficient resistance to deformation to withstandthe torque necessary to fracture the bridges.

The outside diameter of the barrel 33 of ring 27 at its upper end issomewhat less than the inside diameter of the surrounding portion of thecap skirt, so that the flange 32 can be expanded in a manner and for thepurpose subsequently shown.

To provide for insertion of ring 27, the skirt bell portion 15 is formedwith its lip portion 26 initially vertical and its inside diameterslightly larger than the outside diameter of ring 27 across the ribs 31.Ring 27 is pushed into the bell and held with its upper face 28 pressedagainst the shoulder 29. The lip 26 can then be crimped, spun, or rolledin tight against the lower face of ring 27 so that there is no end playbetween the ring and the shell. In order to obviate rotational slack, itis desirable that the ribs 31 or ring 27 be a close fit in the flutes ofcorrugations 30.

FIG. 4 shows the neck and finish of the jar 10 and FIG. 6 shows the cap11 applied thereto to complete the closure. The finish includes externalthreading 34. The thread comprises about two-thirds turn, but it will beunderstood that compound or partial threads or cam lugs may be used, ifdesired. Finishes with threading or the like, particularly suitable forwide-mouth jars are shown in the patent to White, mentioned above. Suchtwist-off arrangements provide desirable quickremoval and reclosurefeatures, yet have good retention characteristics.

A collar 35 is provided immediately below the thread 34. The outsidediameter of collar 35 is about the same as the major diameter of thread34, or slightly larger. Collar 35 defines a downwardly facing shoulder37. Another collar 38, slightly larger in diameter than collar 35 andspaced therefrom, defines an upwardly facing shoulder 39 opposingshoulder 37. A circumferential series of equally spaced serrations orribs 40 extend between shoulders 37 and 39, the ribs being quite sharplypointed as best seen in FIG. 5.

The completed closure, shown in FIG. 6, is effected by pushing cap 11over thread 34, compressing the plastomeric material of the side linerinto conformity with the thread 34. As more fully described in theaforesaid patents, the side liner material has the characteristics oftaking a set under the high pressure exerted thereon, whereby the femalethread therein becomes permanent within the time elapsing betweenclosing and delivery to the ultimate consumer.

The flange 32 of ring 27 is so positioned as to lie opposite the spacebetween the finish shoulders 37 and 39 when cap 11 is telescoped overthe finish the amount required to form the seal and the threading in theliner thereof as above described. Upon pushing the cap over the finish,the expansible flange 32 rides over the threads and collar 35 and thensnaps into position snug under shoulder 37, shoulder 39 serves as a stopto obviate overtravel. The stroke and pressure relief of the tooling areadjusted accordingly, as well understood by those skilled in the cappingtool art.

The diameter across the crests of ribs 40 is larger than the normalinside diameter of flange 32, so that contractive force of the resilientflange forms complementary grooves therein, seizing the flange to theserration ribs and positively inhibiting rotation of the ring 27relative to the finish.

As above described, ring 27 is non-rotatably and non-shiftably held inthe bell of skirt 13. Accordingly, twist-off torque applied to the uppershell portion 14 over-stresses the bridges 41, rupturing them.Thereafter, the upper or prime cap portion 11 can be twisted off. In theweakening band design shown, shearwise elongation of the bridges 41 isnegligible, so that rupture occurs substantially without rotation of thecap relative to the finish. Accordingly, the seal cannot besubstantially disturbed upon attempting to twist the cap, except byrupturing the bridges. The portion of the bell below the bridges drops,exposing the lower portion of ring 27. The ring may be made of brightlycolored plastic, or have indicia along the lower edge, to provide atelltale supplemental to that of bridge fracture.

The preferred embodiment above described incorporates both anti-rotationand anti-rise features. Thus, even should there be some rotational slackor slight slippage, the cap shell will be severed due to tension imposedon the bridges by inhibition of rise. Generally, ring 27 is moreresistant to deformation by twist than by tension imposed by axialrestraint, so that the primary rupture forces are shear forcestangential to the weakening band 16. This is the preferred rupture modefor the type of weakening shown. However, it will be understood that theanti-rise provision alone may be found suflicient in some applications,in which case some modification to the parts may be desirable. The ribs40 can then be omitted. A somewhat thicker anchor flange 32 than thatshown may also be desira ble. The barrel of the ring can be made ofstiff material, somewhat heavier wall or both, in order to minimizeaxial elongation, either locally or generally. The style of shell shirtweakening may be employed which will effect rupture with minimal axialelongation, as for example, by sharply scoring or necking the materialcontinuously around the skirt. Use of relatively high temper stock forthe cap shell can also serve this purpose.

Aluminum is a preferred material for the shell of cap 11 above shown anddescribed. Such material is preferred because of its good finish, easeof formation by bending, drawing, spinning, or rolling, high corrosionresistance and facility of attractive decoration. Because the threadsare formed in the plastic side liner without deformation of the shell,the sometimes unsatisfactory creep and warp characteristics involvedwith threads formed in thin aluminum are not a factor affectingperformance of the preferred form of cap.-

However, it will be understood that other modes of.

skirt thread formation may be used, with or without the side liner, forexample, roll-on, squeeze or crowning techniques. Various types andstyles of top seal liners or gaskets may be used in lieu of thepreferred type shown herein.

While an aluminum shell is preferred for the reasons above stated, tinplate or other materials may be used,

- plain cap of the push-on, twist-off variety.

The foregoing description will suggest to those skilled in the art othermodifications within the scope of the invention as defined in theappended claims.

What is claimed is:

1. A closure cap for a container finish having an external thread meansand a first collar defining a downwardly facing shoulder around the topof the container below said thread;

said cap comprising a top panel and a skirt depending therefrom;

said skirt including a generally cylindrical upper portion adapted forconformation to the finish thread and a lower bell portion of largerdiameter than 1 said upper portion;

a second collar connecting the lower part of the cylindrical portion tothe upper part of the bell portion;

a ring in said bell portion, said ring being axially and rotationallynon-shiftable relative to said bell portion;

said ring having a resiliently expansible inward flange normally ofsmaller inside diameter than said collar and being positioned in saidbell portion for engagement with said lip under the downwardly facingshoulder under the thread when said cap is telescoped over the finish;

- a weakening band around said skirt below said second collar;

an inturned lip formed integral with the lower edge of said bellportion; and

an outwardly extending portion of said ring mounted on said ring at alocation downwardly of said flange and abutting against the uppersurface of said inturned lip whereby said closure cap bell portion isheld against upward motion and when torque is applied to said upperportion in a direction to twist said cap off the container then theskirt ruptures at said weakening band.

2. A closure cap for a container finish having an external thread meansand a first collar defining a downwardly facing shoulder around the neckof the container below said thread, as set forth in claim 1 said capfurther comprising:

lower corrugations in said vertical bell portion defining alternatingaxial ridges and flutes whereby the exterior of the outwardly extendingportion of said ring presses against the ridges and flutes to avoidrelative rotation between said portion and ring.

3. A closure cap for a containerfmish having an external thread and afirst collar defining a downwardly facing shoulder around the neck ofthe container below said thread as set forth in claim 2, said ringfurther comprises:

a telltale material whereby when said weakening band fractures, saidbell portion falls exposing the telltale material.

bination of:

a container having a finish with external thread formation thereon plusa collar thereon below said thread formations defining a downwardlyfacing first shoulder with ribs extending parallel to the side of saidcontainer under said downwardly facing first shoulder; and

a closure cap having a shell including a top panel and a generallycylindrical skirt depending therefrom;

the upper portion of said skirt telescoping over said thread formationsand being conformed to said thread formations;

said skirt including a lower bell portion having corrugations around itslower portion;

a ring insert held fast in said lower portion against endwise movementrelative thereto;

said insert including an inward flange engaged under said shoulder and aseries of corrugations on the exterior surface of said insertdovetailing with cor rugations of said lower bell portion; and

frangible weakening means in said lower portion, said upper portionbeing free of said insert upon fracture of said weakening means whenrotational pressure applied to said upper portion unscrews said upperportion to cause rupture of said weakening means while said ring insertis prevented from rotating by said ribs on said container and said lowerportion below said weakening means separates from said upper portion.

5. A tamper proof package as set forth in claim 4 in which said capfurther comprises:

an inturned lip formed integral with the lower edge of said bellportion, and

an outwardly extending portion of said ring insert for abutting againstthe upper surface of said inturned lip whereby said closure cap lowerbell portion is held against upward motion.

6. A tamper proof package as set forth in claim 4 in which said lowerbell portion further comprises:

a plurality of vertical corrugations in said lower bell portion belowsaid frangible weakening means defining alternating axial ridges andflutes whereby the exterior of the outwardly extending portion of saidinsert presses against the ridges and flutes to avoid relative rotationbetween said bell portion and said insert.

7. A tamper proof package as set forth in claim 6 in which said insertfurther comprises:

a brightly colored material whereby when said weakening band fracturessaid bell portion falls to expose said brightly colored material.

1. A closure cap for a container finish having an external thread meansand a first collar defining a downwardly facing shoulder around the topof the container below said thread; said cap comprising a top panel anda skirt depending therefrom; said skirt including a generallycylindrical upper portion adapted for conformation to the finish threadand a lower bell portion of larger diameter than said upper portion; asecond collar connecting the lower part of the cylindrical portion tothe upper part of the bell portion; a ring in said bell portion, saidring being axially and rotationally non-shiftable relative to said bellportion; said ring having a resiliently expansible inward flangenormally of smaller inside diameter than said collar and beingpositioned in said bell portion for engagement with said lip under thedownwardly facing shoulder under the thread when said cap is telescopedover the finish; a weakening band around said skirt below said secondcollar; an inturned lip formed integral with the lower edge of said bellportion; and an outwardly extending portion of said ring mounted on saidring at a location downwardly of said flange and abutting against theupper surface of said inturned lip whereby said closure cap bell portionis held against upward motion and when torque Is applied to said upperportion in a direction to twist said cap off the container then theskirt ruptures at said weakening band.
 2. A closure cap for a containerfinish having an external thread means and a first collar defining adownwardly facing shoulder around the neck of the container below saidthread, as set forth in claim 1 said cap further comprising: lowercorrugations in said vertical bell portion defining alternating axialridges and flutes whereby the exterior of the outwardly extendingportion of said ring presses against the ridges and flutes to avoidrelative rotation between said portion and ring.
 3. A closure cap for acontainer finish having an external thread and a first collar defining adownwardly facing shoulder around the neck of the container below saidthread as set forth in claim 2, said ring further comprises: a telltalematerial whereby when said weakening band fractures, said bell portionfalls exposing the telltale material.
 4. A tamper-resistant packagecomprising the combination of: a container having a finish with externalthread formation thereon plus a collar thereon below said threadformations defining a downwardly facing first shoulder with ribsextending parallel to the side of said container under said downwardlyfacing first shoulder; and a closure cap having a shell including a toppanel and a generally cylindrical skirt depending therefrom; the upperportion of said skirt telescoping over said thread formations and beingconformed to said thread formations; said skirt including a lower bellportion having corrugations around its lower portion; a ring insert heldfast in said lower portion against endwise movement relative thereto;said insert including an inward flange engaged under said shoulder and aseries of corrugations on the exterior surface of said insertdovetailing with corrugations of said lower bell portion; and frangibleweakening means in said lower portion, said upper portion being free ofsaid insert upon fracture of said weakening means when rotationalpressure applied to said upper portion unscrews said upper portion tocause rupture of said weakening means while said ring insert isprevented from rotating by said ribs on said container and said lowerportion below said weakening means separates from said upper portion. 5.A tamper proof package as set forth in claim 4 in which said cap furthercomprises: an inturned lip formed integral with the lower edge of saidbell portion, and an outwardly extending portion of said ring insert forabutting against the upper surface of said inturned lip whereby saidclosure cap lower bell portion is held against upward motion.
 6. Atamper proof package as set forth in claim 4 in which said lower bellportion further comprises: a plurality of vertical corrugations in saidlower bell portion below said frangible weakening means definingalternating axial ridges and flutes whereby the exterior of theoutwardly extending portion of said insert presses against the ridgesand flutes to avoid relative rotation between said bell portion and saidinsert.
 7. A tamper proof package as set forth in claim 6 in which saidinsert further comprises: a brightly colored material whereby when saidweakening band fractures said bell portion falls to expose said brightlycolored material.